Pistella franciscana, Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015

Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015, Terebellidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 484-576 : 534-539

Pistella franciscana n. sp.

( Figs 2 H–I, 32–35)

Type material. Holotype: AM W.45445, MI QLD 2444, north of North Point, 14°38'36"S, 145°27'09"E, complete specimen, in excellent state of preservation, ~ 15 mm long, 0.6 mm wide. Paratypes: AM W.47715, CReefs, LI–10– 0 33, MI QLD 2198, Watsons Bay, 14°39'30"S, 145°26'56"E, incomplete specimen, in excellent state of preservation; AM W.44593, MI QLD 2394, mounted on 2 SEM pins; AM W.44964, MI QLD 2435 (photographed).

Other material examined. AM W.44957, MI QLD 2429; AM W.44626, MI QLD 2414; AM W.44628, MI QLD 2416; AM W.45441, MI QLD 2444; AM W.45145, MI QLD 2440; AM W.45447, MI QLD 2444 (3); AM W.45146, MI QLD 2441; AM W.45446, MI QLD 2444.

Comparative material examined. Holotype of Pistella anthela Hutchings & Glasby, 1990 , AM W.203515. Paratypes of Pistella anthela , AM W.203516, AM W.203517, AM W.203520, AM W.203521, AM W.203523. Holotype of Pistella lornensis ( Pearson, 1969) , ZB 1968: 15. Paratype of Pistella lornensis , ZB 1968: 16. Nontype of Pistella lornensis , ZMUC Pol 1744.

Description. In life, body pink to greenish, with colourless buccal tentacles and mid-ventral shields with bright red posterior section ( Fig. 2 H–I). Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part shelf-like ( Figs 32 E–F, J–K; 33A, D, F, J). Buccal tentacles, longer than region with notopodia in life, but shorter after preservation ( Figs 2 H–I; 32A–F, J–K; 33A–K). Peristomium forming lips; hood-like upper lip, short, as wide as long; small, swollen lower lip, restricted to oral area ( Figs 32 E, J; 33G–H). Segment 1 reduced dorsally, expanded ventrally with paired ventral lobes lateral to mouth, connected to each other by low lobe marginal to mouth; segment 2 with paired ventro-lateral lobes connected to each other by protruding mid-ventral crest, lobes almost semi-circular, covering posterior half of segment 1; segment 3 with pair of triangular, distally rounded lateral lobes, lobes short, only covering posterior part of segment 2, dorsal margins aligned with line of notopodia, ventral margins terminating in line with the mid-length of subsequent neuropodial tori ( Figs 32 A–F, J– K; 33A–L). Anterior segments not markedly inflated dorsally. Paired dorso-lateral plumous branchiae present on segment 2, single pair, frequently one branchia missing, presumably lost by predation, supported by the fact that some individuals have branchiae of remarkably different sizes ( Figs 32 A–F, K; 33A–F, I–K); each branchia with conspicuous, crenulate basal stem, and branchial filaments originating in a spiral at tip; branchial filaments dichotomously branching for 1–2 levels, with relatively long tips, bearing ciliary tracks laterally and around bald tips ( Fig. 33 A–F, I–K, M–N). Anterior segments with glandular, rectangular to trapezoidal, smooth to slightly corrugated mid-ventral shields; shields typically divided in two parts, anterior part white, posterior part bright red, not always visible after preservation ( Figs 2 H–I; 32A, D–E, J–K; 33A, C, G–I, K). Short and conical notopodia beginning from segment 4, typically extending for 17 segments, until segment 20. Winged notochaetae in both rows, broadly-winged, wings as broad as width of shaft or broader ( Figs 34 C–G; 35A–B, F). Neuropodia present from segment 5, as low ridges until termination of notopodia, as low pinnules thereafter. Neurochaetae throughout as short-handled avicular uncini, arranged in partially to completely intercalated double rows from segment 11 until termination of notopodia; uncini with dorsal button at mid-length of base, conspicuous at least until termination of notopodia, and crest with 3–4 transverse rows of secondary teeth ( Figs 34 B, H–M; 35C–E, G–K). Nephridial and genital papillae usually present on segments 3 and 6–7, respectively, the latter posterior and dorsal to notopodia ( Fig. 33 D, K, L). In addition there are additional minute papillae on segments 2–6 which are labelled in Fig. 33 L, the function of which is unknown, perhaps they are sensory. Pygidium with larger ventral papillae ( Figs 2 H–I; 32A–B, G–I; 33 O; 36A). Mucous tube.

Remarks. Pistella franciscana n. sp. differs from the only other known Australian species of Pistella , P. anthela ( Hutchings & Glasby, 1990) described from the Dampier Archipelago in Western Australia, by the shape and arrangement of lateral lobes. In the new species no lobes continue across the dorsum as glandular ridges as they do in P. an t he l a. The tips of the branchial filaments are completely bald surrounded by well developed cilated sides ( Fig. 33 M, N), whereas those of P. a nt he l a appear ciliated throughout including the tips (JMMN pers observ.).

The type species of the genus, P. lornensis ( Pearson, 1969) , has much larger lobes on segments 1–3, those of segment 1 extending ventrally from one side to another of body, lobes of segment 2 much longer, almost reaching level of prostomium and with straight distal margins, and those of segment 3 extending to the corners of the midventral shield, while in P. franciscana n. sp. the lobe of segment 1 is only marginal to mouth, lobes of segment 2 are almost semi-circular and only cover the posterior part of segment 1, and those of segment 3 are only lateral.

Etymology. We name this species as “ franciscana ” due to the unusual pattern of ciliation of branchial filaments, which encircle a bald tip, resembling the head of Franciscan monks from the Middle Ages.

Type locality. North of North Point, 14°38'36"S, 145°27'09"E, Lizard Island, GBR, Australia.

Distribution. Widespread around Lizard Island.

Figures

FIGURE 2. Live specimens. A – B. Pista kristiani n. sp. AM W. 45451, MI QLD 2445; C – D. Lanicides rubra n. sp. AM W. 44272, MI QLD 2344; E – G. Eupolymnia chlorobranchiata n. sp. AM W. 45455, MI QLD 2446; H – I. Pistella franciscana n. sp. H. Discarded specimen; I. AM W. 44593, MI QLD 2394; J – L. Loimia tuberculata n. sp; J – K. Spec. AM W. 44280, MI QLD 2359; L. Discarded specimen. Photos: A – K—Alexander Semenov, L—Gary Cranitch.

FIGURE 32. Pistella franciscana n. sp. AM W. 45445: A – B. Entire worm, ventro-lateral and dorsal views, respectively; C – F. Anterior ends, dorsal, right lateral, ventral and left lateral views, respectively; G – I. Posterior end, in progressively lower magnifications, ventral views; J – K. Close ups of the anterior end, ventral and right lateral views, respectively. Numbers refer to segments. Abbreviations: ul = upper lip. Scale bars: A – B = 0.5 mm, C, E, G, K = 0.2 mm, D, F, H – I = 0.3 mm, J = 0.15 mm.

FIGURE 33. Pistella franciscana n. sp. AM W. 44593: A – E. Anterior end, left ventro-lateral, right lateral, right ventro-lateral, left lateral and right dorso-lateral views, respectively; F – K. Close ups of the anterior end, dorsal, left and right (2) ventro-lateral views, left dorso-lateral and left lateral views, respectively; L. Close up of segments 2 – 8, left lateral view, white and black arrows point to the two sets of papillae; M – N. Progressively closer views of the branchiae; O. Posterior end, left lateral view. Numbers refer to segments. Abbreviations: ll = lower lip, P = basal part of prostomium, ul = upper lip, * = distal part of prostomium. Scale bars: A, C – E = 200 µm, B = 300 µm, F, I = 150 µm, G, L = 70 µm, H, J – K, O = 100 µm, M = 40 µm, N = 10 µm.

FIGURE 34. Pistella franciscana n. sp. AM W. 44593: A. Pygidium, frontal view; B. Neuropodium, segment 16; C – D. Notochaetae, segment 8, general and chaetae from anterior row, respectively; E – G. Notochaetae of segment 15, general, chaetae from anterior and posterior rows, respectively; H. Uncini, segment 10; I – J. Uncini, segment 15 under higher magnifications; K. Uncini, segment 24; L – M. Posterior uncini, under higher magnifications. Scale bars: A = 20 µm, B, D, L = 7 µm, C = 15 µm, E – G = 10 µm, H, M = 2 µm, I, K = 5 µm, J = 3 µm.